Isolated DC-DC converters include power transfer circuitry to power an otherwise unpowered voltage domain from a powered voltage domain. The power transfer typically occurs across an isolation barrier. The converter includes a pair of electrically-isolated voltage domains, one of which is powered. The powered voltage domain may transfer power to an otherwise unpowered voltage domain so as to drive circuitry in the unpowered voltage domain.
DC-DC converters commonly begin operation at a nominal voltage in the unpowered voltage domain that must build to a voltage level that allows for proper operation of the DC-DC converter. However, when the converter is initially started, the circuit components of the converter experience a large in-rush of current. The in-rush current delays proper operation of the DC-DC converter because the converter circuit components are delayed from properly operating until the ringing resulting from the large in-rush current subsides.
There is a need for a system and method to reduce the in-rush current and allow for a more gradual transition between starting operation and continued operation of the DC-DC converter.